The great accuracy test: Part 3
by B.B. Pelletier
Well, when was the last time we had a discussion this large on this blog? You were talking on yesterday’s report and on the first part of this series, all at the same time.
And, we were talking apples, oranges, cinnamon wafers and pseudo-dadaism in the post-war cinema! All at the same time.
So, once more, I will attempt to state what it is that we’re trying to do. We’re trying to discover some things that, if applied in certain ways, will always help improve accuracy. As I explained to several readers, the artillery hold is one such thing. I didn’t invent it. I just gave it a name so I could talk about it, and people would understand what I was talking about.
Now we’re looking for more things like the artillery hold that, if applied properly, will always improve your accuracy.
Today, you’re going to have to read the report very carefully, because the results you are about to see are the opposite of what you expect. But please read everything, and I’ll explain what I think has happened.
Yesterday, I tried using common reading glasses to improve the accuracy as I was shooting an Air Venturi Bronco rifle. I shot 6 groups of 10 shots each at targets 25 yards away. There were three pellets that I tested. Each pellet was shot first without me wearing reading glasses and then again with the glasses on. I showed you the targets as they occurred, and I told you after the shooting was finished that I could not discern any advantage to shooting with reading glasses.
Now I’ll show you what happened when I pre-sorted the pellets by weight before shooting. We’ll compare the best of the two targets shot yesterday with each pellet against a target shot with that same pellet sorted into a group of 10 pellets that weigh the same, down to the nearest tenth of a grain.
Those readers who do not have problems with their eyes can do today’s test as well by simply shooting two 10-shot groups — one with sorted pellets and one without.
The first pellet shot was the same 8.4-grain JSB Exact domed pellet that I used to begin the test. I used that pellet because back when I tested the Bronco for you, it turned in the best results.
I weighed all the pellets on an electronic powder scale set to register grains. The scale weighs to the nearest tenth grain, so that was how I grouped them. Only those pellets that registered the exact same weight on this scale would be used.
Sorting the JSBs proved to be a big surprise for me, because they were not that uniform. Weights varied from 8.1 to 8.6 grains for a pellet that is nominally supposed to weigh 8.4 grains. I do appreciate that anything manmade will vary, but it has been my experience that premium pellets like these JSBs do not vary that much. But these did. In fact, I had to use the pellets that weighed 8.3 grains, because there weren’t enough of the ones that weighed 8.4 grains.
Then, I shot the group. I took as much care as I had with all the other groups, plus these groups came after the first test, so I had 60 shots under my belt by this time. I expected to see a super-tight group.
It looks like only 6 pellets went through, but the holes next to the numbers 7 and 6 on the target have multiple pellets through them. I can tell that from the back of the target paper. This group of pellets sorted by weight measures 2.061 inches between centers.
That group surprised me a lot, I can tell you. I expected a lot better performance from sorted pellets. Look at yesterday’s best group, shot with unsorted pellets.
Ten shots with the same 8.4-grain JSB Exact pellet, only these were randomly selected from the tin. This group measures 2.085 inches between centers, which is only a trifle larger than the sorted group, above. These happened to be the ones shot while I was wearing reading glasses.
The next pellet to test was the BSA Wolverine. In sharp contrast to the JSB Exacts, above, these pellets were extremely consistent in weight, and I rejected only one while picking 10 to shoot.
What a contrast! Only one pellet was found not to weigh 8.3 grains, and it weighed 8.2 grains. These pellets are extremely consistent in weight.
Well, I figured the consistent Wolverines were going to win the day, except they hadn’t been that accurate in the first two tests, and they should have been if weight variation matters to accuracy. And this time they were a real surprise!
This group of 10 sorted BSA Wolverine pellets measures 2.481 inches on centers. It’s the worst group of the test (including all the shooting seen both yesterday and today).
I was really stumped, but please hang on because there’s an explanation coming. First, though, have a look at the best target shot with unsorted Wolverine pellets.
This Wolverine target shot yesterday without reading glasses measured 2.048 inches between centers. The target shot while wearing glasses measured the same size. Both are considerably smaller than today’s target shot with pellets sorted by weight.
The last pellet I tried was the RWS R-10 heavy pellet. I assumed that because it’s a target pellet it would be very uniform in weight. WRONG!
And, you may remember that the R-10 pellets were by far the most accurate pellets of all in the first test. Well, this time they surprised me.
This group of sorted RWS R-10 pellets measures 1.743 inches between centers. It’s the largest group of R-10 fired. While the best group of the day, it’s larger than the random R-10s fired the day before.
Let’s look at the best R-10 group, fired during the first test.
This group of R-10 pellets shot without reading glasses measures 1.158 inches between centers. Not only is it better than the group sorted by weight, it’s the best group of all the shooting done thus far.
Okay, here comes the explanation I promised. All these targets from yesterday and today were shot at the same time, so these three final targets shot with pellets sorted by weight were shot last. They represent shots 61 through 90.
I can’t prove it, but I believe that pellets of a uniform weight should not be less accurate than the same pellets of random weights. The results of today’s test seem to indicate that sorted pellets are less accurate than unsorted pellets if we go just by the group sizes, but I think something else is at work here. I believe there’s a whole lot of test bias in what I have reported both yesterday and today. I believe today’s results were skewed to the bad end of the scale because they were the last groups I shot and I was getting tired from all the sighting techniques I was undergoing to use the reading glasses.
As twotalon observed, are we talking about something so ambiguous that it will be different for every shooter? I don’t think so. But I do think that the test design I have done yesterday and today doesn’t work.
I believe the problem is lighting, as in not enough light on the target in these tests. I say that because today I went to the outdoor range and shot two 10-shot groups with a .30 caliber M1 Carbine at 50 yards and each group measured about three inches across the two widest shots. The M1 Carbine has a very large peep sight that has been criticized for its crudity, yet I shot well with it using the same reading glasses that failed in these tests. And, today I was able to see the bull quite well, even though it was twice as far away.
Finally, even out at 25 yards, the uniformity of pellet weight appears to not be much of a factor. The BSA Wolverines that were the most uniform weight did worst of all. Of course, the results of these tests are so large and open that all kinds of errors and truths may be camouflaged within.
From these two tests that I will have to consider as failed, we can draw some important conclusions. First, I need to either use a scope or a dot sight when conducting accuracy tests. Tomorrow, I’ll show you some groups that demonstrate that I can still shoot well with a scope.
Perhaps a future experiment might be for me to put a dot sight on the same Bronco and re-shoot this test. I’ll use the same three types of random pellets (not sorted by weight) for that test, then I’ll mount a scope on the rifle and shoot the same test again. If there’s a definite difference between the results from the two optical instruments (and I’m thinking there will be), I’ll select the most accurate optical sight and rerun the weight-sorted test.
Meanwhile, you can select as much of this test as you desire and try to do it yourself. When we’re finished, we should know the value of pellets sorted by weight and those of you who have old eyes like me might give the reading glasses trick a try, but only outdoors or where there’s a lot of light.